The spring hinge assembly of this invention includes the frame hinge section and a leaf hinge section connected by link members each having two pivots. The frame hinge section comprises a base plate and a link supporting plate. The link supporting plate is longitudinally displaceable with respect to the base plate and may be adjusted and secured perpendicularly to the direction of displacement. The hinge sections face one another and are under spring action with respect to each other. The door leaf hinge section is held by a spring latch in the closed position of the hinge assembly.
Spring hinge assemblies of this type are well known and include a link member having an extension which projects into the frame hinge section and coacts with a lever member which is under spring action. The lever member is either hinged on the frame hinge section or with a pulley which is arranged on the lever member. In one constructional form of a spring hinge, helical compression springs are used as springs for the lever members. Generally there is little space available on the link supporting plate. Consequently, the helical compression springs have a comparatively small number of turns, thereby producing a hard springing action. With another known constructional form, the springs have long legs which extend over the full length of the link supporting plate. Consequently, when adjusting and fixing screws are arranged between the supporting plate and the base plate, the long leg spring includes a comparatively broad link supporting plate so that the legs of the spring are able to be arranged in the U formation of the supporting plate. As a whole the link supporting plate with a relatively large overall length and width is obtained. Nevertheless, the spring force of the spring is not very strong.
With another constructional form, a helical torsion spring is provided and the legs thereof are supported at one end on the pivotal part and on the other end on the fixed hinge component. The fitting of such a helical torsion spring is comparatively difficult. Furthermore, the helical torsion spring necessitates a comparatively large height of the frame hinge component and of the link supporting plate if the spring legs of the torsion spring are not to be overstressed. In all of the prior art constructions as set forth herein, the arrangement and fitting of the spring assembly for the lever in the link supporting plate is not satisfactory.